Various tubing connectors have been developed to secure lengths of round or square tubing together either with the tubing axes coincident or at right angles so that the tubing can be assembled to provide a structural framework. The following patents are illustrative of connectors in this category:
______________________________________ 3,000,656 Hollaender 3,642,310 Hudson 3,645,569 Reilly 3,711,133 Werner 3,731,958 Offenbroich 3,873,220 Kashiwabara 4,023,913 Berkowitz 4,076,429 Berkowitz 4,111,577 Kiyosawa 2,006,297 Kyburz (U.K.) ______________________________________
Typically the base block of the various tubing connectors of the prior art are cubical, with connecting arms projecting from one or more faces. However, it is not desirable to have connecting arms projecting from all six faces if only two or three of the connecting arms are going to be used at a particular joint. Accordingly, if the connectors are molded, molds must be made for a base block with various numbers of projecting connecting arms. U.S. Pat. No. 3,642,310 uses clips to fasten tubing lengths to a right angle joint and hence does not require a variety of molds. The clips, however, detract from the appearance of the joint.